textproduct: Rapid City

KEY MESSAGES

- Light precipitation expected tonight into Friday, transitioning from rain to snow early Friday morning, minimal accumulations are expected

- Gusty northwesterly winds develop Friday with gusts up to 40-50 mph

- Above-average temperatures and elevated fire weather return for the weekend

DISCUSSION

(This Evening Through Thursday) Issued at 1259 PM MST Thu Mar 5 2026

Current upper-air water vapor analysis depicts split-flow across central/eastern CONUS, with synoptic scale troughing over western CONUS, and a shortwave trough over the Great Lakes region. WV imagery indicates patchy cloud cover over central SD and increased cloud cover and rain/snow showers over western MT/eastern ID (the system that will bring some of the moisture to the region tonight/Friday). Current surface observations show warm, dry air over much of the forecast region with lingering fog over northwest SD (towards the ND/SD state line). A wide range of temperatures are present (due to the fog) ranging from the low 30s to low 60s. A pocket of stronger southerly winds is currently located over south- central SD, gusting to 35 mph, while the rest of the region is experiencing variable winds at 15 mph or less. With decreasing cloud cover, RH values have dropped into the 20s and 30s percent (except for northwestern SD) and are expected to continue to drop into the mid teens, from the foothills eastward. Stronger winds will not increase for much of the region until this evening; therefore, a Red Flag Warning will likely not be issued. However, much of the region is still ready to burn (a small grassland fire occurred overnight by Fairburn, SD). Due to these conditions, elevated fire weather conditions are still present across much of the area ahead of the system that will move through later this evening/Friday.

For the system moving through tonight into Friday, most ensembles (GEFS, SREF, NBM) are showing a decrease in snowfall and QPF totals for the forecast region. This is potentially due to the surface-low not strengthening as much as previous runs, the dry air ahead of the system eating into the moisture, and the track of the low shifting farther south and east, allowing for more precipitation to move into WY/CO, reducing the amounts that would move through the region. The current NBM-CONUS run shows <20 percent chance for >2 inches of snowfall for the northern Black Hills and a ~20-30 percent chance for >2 inches across south-central SD. QPF values are showing a similar trend with a ~25-35 percent chance for >0.10 inch for the northern Black Hills, while central and south-central SD have a ~35- 55 percent chance for >0.10 inch (higher chances are over south- central SD).

Precipitation is expected to start out as rain before transitioning to snow early Friday morning, and continue as snow for the remainder of Friday before the system moves out of the region Friday evening. Snow banding will begin to move through the region early Friday morning, setting up where higher snowfall amounts are most likely to occur. Temperatures will play a large role in when and where rain transitions to snow and how much accumulation occurs. Due to the warm, dry conditions the last two days, snow accumulations will likely be minimal. Gusty northwesterly/northerly winds will develop this evening and linger through the night before increasing during the day Friday as the cold front moves through, with gusts reaching 40-50 mph. Due to these gusty winds, a Wind Advisory may be justified during the day tomorrow along and to the east of the foothills.

This weekend is expected to see a warming trend with above-average temperatures and elevated fire weather conditions returning by Sunday. Another disturbance could move through the region at the beginning of next week, brining another shot at rain and snow. However, confidence is currently low on potential impacts.

AVIATION

(For the 18Z TAFS Through 18Z Friday) Issued At 1033 AM MST Thu Mar 5 2026

Dense fog is quickly eroding across NW SD into SW ND with lingering IFR/LIFR conditions through 19z. Otherwise, VFR conditions are expected through this afternoon. A cold front will bring increasing chances of rain/snow and MVFR/IFR conditions tonight into Friday afternoon, particularly across south-central SD. Gusty north/northwest winds will develop overnight, especially just east of the Black Hills.

FIRE WEATHER

Issued At 1259 PM MST Thu Mar 5 2026

Elevated fire weather conditions are expected to return this weekend as temperatures rebound into the 60s to low 70s with relative humidity values dropping into the low 20s. Areas of the forecast region may experience a wetting rain through Friday, however, conditions will deteriorate by Sunday. Breezy westerly winds will develop over northwest and southwest South Dakota Saturday and again on Sunday, gusting to 35-45 mph.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.